In an interrupted time-series quasi-experimental design, researchers
A) choose two existing groups of people, one of which is randomly assigned to the experimental group and the other to the control group.
B) observe a dependent variable over extended periods of time both before and after a treatment is instituted to detect changes associated with the treatment.
C) select a control group after data have been collected to control for holes in the internal validity of a natural or quasi experiment
D) add a pretest to determine whether there are preexisting differences between the experimental and the control group.

Question

Quizplus · Accepted Answer

In interrupted time-series quasi-experimental design, researchers observe a dependent variable over extended periods of time both before and after a treatment is instituted to detect changes associated with the treatment. This design does not involve randomly assigned groups or selection of a control group after data collection. A pretest may be added to determine preexisting differences but it is not specific to this design.

In an Interrupted Time-Series Quasi-Experimental Design, Researchers